As a device for drying the surface necessary to be dried by feeding a drying gas flow to a long belt-shaped drying object having the surface necessary to be dried such as coating film and the like, for example, those disclosed in JP-B-48-44151/1973, JP-B-51-22115/1975, JP-A-7-289971/1995 and JP-A-9-152274/1997 (the term "JP-A" as used herein means a Kokai-Publication, i.e., "unexamined laid-open Japanese patent application" and the term "JP-B" as used herein means a Kokoku-Publication, i.e., "examined published Japanese patent application") are known.
In a conventional drying device, as disclosed in, for example, JP-A-7-289971/1995, a drying gas flow (blow) is sent from a blower through a duct (pipe line) to a temperature and relative humidity control unit for controlling temperature and humidity, and then, fed through another duct to a blowing unit (dryer) of the drying gas flow in a drying room.
A gas flow, which has been exhausted for drying by colliding with a coated surface (the surface necessary to be dried) of a drying object in a drying room, is used for feeding again into another drying room after being recovered through an exhaust vent of the drying room and then heated up to a desired temperature in a duct equipped with a heater for heating the gas flow up to any desired temperature. As disclosed in JP-A-9-152274/1997, in some case, the gas flow before feeding is admixed with a fresh gas if necessary and then reused.
An embodiment of a conventional drying device is shown in reference to FIG. 5 in the accompanying drawings. FIG. 5 is a schematic view showing a general composition of units contained in a conventional drying device.
A conventional drying device shown in FIG. 5 has a component unit (or assembly unit) P including ducts (D2, D3, D4) so as to let a gas flow come out of a blower 41a, pass through an inner space of temperature and relative humidity control unit 42a, helical dryer 43a, and drying room 44a consecutively in this order, and arrive at a blower 41b. This details will be explained as follows.
The blower 41a feeds a gas blow, after being dehumidified in a dehumidifying facility 40 and then passing through a duct D1, through the duct D2 into the temperature and relative humidity control unit 42a. The temperature and relative humidity control unit 42a can set the temperature and the humidity of the gas flow to a predetermined value which is appropriate for drying a drying object. The gas flow, after setting the temperature and the humidity to the predetermined value in the temperature and relative humidity control unit 42a, is fed through the duct D3 to an end of the helical dryer 43a, which has approximately a cylindrical shape, into an inner space of the helical dryer.
The helical dryer 43a is installed in the drying room 44a (the inner space of the dryer). In the outer periphery (wall) of the helical dryer 43a having a cylindrical shape, exhaust vents (e.g., holes or slits) are disposed, and a drying gas flow is exhausted out of the exhaust vents. A drying object is placed so as to bring its surface necessary to be dried into contact with a drying gas flow exhausted out of the exhaust vents of the helical dryer 43a, so that the surface of the drying object necessary to be dried is dried. The gas flow after drying the drying object will pass through the duct D4 and arrive at a blower 41b placed outside the drying room 44a.
The conventional drying device shown in FIG. 5 further has a component unit Q including ducts (D5, D6, D7) arranged so as to make a gas flow come out of a blower 41b, pass through temperature and relative humidity control unit 42b, helical dryer 43b, and drying room 44b in this order, and arrive at a blower 41c.
The conventional drying device shown in FIG. 5 also has a component unit R including ducts (D8, D9, D10) arranged so as to make a gas flow come out of a blower 41c, pass through temperature and relative humidity control unit 42c, helical dryer 43c, and drying room 44c in this order, and arrive at a blower 41d.
The conventional drying device shown in FIG. 5 still more has a component unit S including ducts (D11, D12, D13) arranged so as to make a gas flow come out of a blower 41d, pass through temperature and relative humidity control unit 42d, helical dryer 43d, and drying room 44d in this order, and arrive at a dehumidifying facility 40.
The blowers, the temperature and relative humidity control units, the helical dryers and the drying rooms found in the component units Q, R and S are same with the blower 41a, the temperature and relative humidity control unit 42a, the helical dryer 43a and the drying room 44a found in the component unit P, respectively, and the former units have the same functions as the latter ones, respectively.
A gas flow, returned through the duct D13 to the dehumidifying facility 40, is dehumidified, passed through the duct D1 and fed into the blower 41a. Then, the aforementioned procedure is repeated.
In case of drying a long web-shaped drying object having a surface necessary to be dried by using the conventional drying device shown in FIG. 5, each drying room has slits through which a drying object passes, rolls for guide and the like, so that the drying object can be passed through the drying rooms 44a, 44b, 44c and 44d successively. Further, the drying gas flow can be fed out of the helical dryers installed in the drying rooms, respectively. Consequently, the drying object can be dried.